Problem: $\begin{aligned}&\phantom{{\times}}4\\ \\ &\underline{\times1} \end{aligned}$
Solution: We can think of ${4} \times {1}$ as $4$ rows of $1$ circle. How many circles are there? ${1}$ ${4}$ ${\color{#9A72AC}{1}}$ ${3}$ ${\color{#9A72AC}{2}}$ ${2}$ ${\color{#9A72AC}{3}}$ ${1}$ ${\color{#9A72AC}{4}}$ $\begin{aligned}&\phantom{{\times}}4\\ \\ &\underline{\times1}\\ \\ &\phantom{{\times}}C4 \end{aligned}$